1 /* 2 * Copyright (c) 1994 Christos Zoulas 3 * Copyright (c) 1995 Frank van der Linden 4 * Copyright (c) 1995 Scott Bartram 5 * All rights reserved. 6 * 7 * Redistribution and use in source and binary forms, with or without 8 * modification, are permitted provided that the following conditions 9 * are met: 10 * 1. Redistributions of source code must retain the above copyright 11 * notice, this list of conditions and the following disclaimer. 12 * 2. Redistributions in binary form must reproduce the above copyright 13 * notice, this list of conditions and the following disclaimer in the 14 * documentation and/or other materials provided with the distribution. 15 * 3. The name of the author may not be used to endorse or promote products 16 * derived from this software without specific prior written permission 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 28 * 29 * from: svr4_util.c,v 1.5 1995/01/22 23:44:50 christos Exp 30 */ 31 32 #include <sys/cdefs.h> 33 __FBSDID("$FreeBSD$"); 34 35 #include <sys/param.h> 36 #include <sys/lock.h> 37 #include <sys/malloc.h> 38 #include <sys/mutex.h> 39 #include <sys/namei.h> 40 #include <sys/proc.h> 41 #include <sys/systm.h> 42 #include <sys/vnode.h> 43 44 #include <machine/stdarg.h> 45 46 #include <compat/linux/linux_util.h> 47 48 const char linux_emul_path[] = "/compat/linux"; 49 50 /* 51 * Search an alternate path before passing pathname arguments on 52 * to system calls. Useful for keeping a separate 'emulation tree'. 53 * 54 * If cflag is set, we check if an attempt can be made to create 55 * the named file, i.e. we check if the directory it should 56 * be in exists. 57 */ 58 int 59 linux_emul_find(td, sgp, path, pbuf, cflag) 60 struct thread *td; 61 caddr_t *sgp; /* Pointer to stackgap memory */ 62 char *path; 63 char **pbuf; 64 int cflag; 65 { 66 char *newpath; 67 size_t sz; 68 int error; 69 70 error = linux_emul_convpath(td, path, (sgp == NULL) ? UIO_SYSSPACE : 71 UIO_USERSPACE, &newpath, cflag); 72 if (newpath == NULL) 73 return (error); 74 75 if (sgp == NULL) { 76 *pbuf = newpath; 77 return (error); 78 } 79 80 sz = strlen(newpath); 81 *pbuf = stackgap_alloc(sgp, sz + 1); 82 if (*pbuf != NULL) 83 error = copyout(newpath, *pbuf, sz + 1); 84 else 85 error = ENAMETOOLONG; 86 free(newpath, M_TEMP); 87 88 return (error); 89 } 90 91 int 92 linux_emul_convpath(td, path, pathseg, pbuf, cflag) 93 struct thread *td; 94 char *path; 95 enum uio_seg pathseg; 96 char **pbuf; 97 int cflag; 98 { 99 struct nameidata nd; 100 struct nameidata ndroot; 101 int error; 102 const char *prefix; 103 char *ptr, *buf, *cp; 104 size_t len, sz; 105 106 GIANT_REQUIRED; 107 108 buf = (char *) malloc(MAXPATHLEN, M_TEMP, M_WAITOK); 109 *pbuf = buf; 110 111 prefix = linux_emul_path; 112 for (ptr = buf; (*ptr = *prefix) != '\0'; ptr++, prefix++) 113 continue; 114 sz = MAXPATHLEN - (ptr - buf); 115 116 if (pathseg == UIO_SYSSPACE) 117 error = copystr(path, ptr, sz, &len); 118 else 119 error = copyinstr(path, ptr, sz, &len); 120 121 if (error) { 122 *pbuf = NULL; 123 free(buf, M_TEMP); 124 return error; 125 } 126 127 if (*ptr != '/') { 128 error = EINVAL; 129 goto keeporig; 130 } 131 132 /* 133 * We know that there is a / somewhere in this pathname. 134 * Search backwards for it, to find the file's parent dir 135 * to see if it exists in the alternate tree. If it does, 136 * and we want to create a file (cflag is set). We don't 137 * need to worry about the root comparison in this case. 138 */ 139 140 if (cflag) { 141 for (cp = &ptr[len] - 1; *cp != '/'; cp--); 142 *cp = '\0'; 143 144 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td); 145 error = namei(&nd); 146 *cp = '/'; 147 if (error != 0) 148 goto keeporig; 149 } 150 else { 151 NDINIT(&nd, LOOKUP, FOLLOW, UIO_SYSSPACE, buf, td); 152 153 if ((error = namei(&nd)) != 0) 154 goto keeporig; 155 156 /* 157 * We now compare the vnode of the linux_root to the one 158 * vnode asked. If they resolve to be the same, then we 159 * ignore the match so that the real root gets used. 160 * This avoids the problem of traversing "../.." to find the 161 * root directory and never finding it, because "/" resolves 162 * to the emulation root directory. This is expensive :-( 163 */ 164 NDINIT(&ndroot, LOOKUP, FOLLOW, UIO_SYSSPACE, linux_emul_path, 165 td); 166 167 if ((error = namei(&ndroot)) != 0) { 168 /* Cannot happen! */ 169 NDFREE(&nd, NDF_ONLY_PNBUF); 170 vrele(nd.ni_vp); 171 goto keeporig; 172 } 173 174 if (nd.ni_vp == ndroot.ni_vp) { 175 error = ENOENT; 176 goto bad; 177 } 178 179 } 180 181 NDFREE(&nd, NDF_ONLY_PNBUF); 182 vrele(nd.ni_vp); 183 if (!cflag) { 184 NDFREE(&ndroot, NDF_ONLY_PNBUF); 185 vrele(ndroot.ni_vp); 186 } 187 return error; 188 189 bad: 190 NDFREE(&ndroot, NDF_ONLY_PNBUF); 191 vrele(ndroot.ni_vp); 192 NDFREE(&nd, NDF_ONLY_PNBUF); 193 vrele(nd.ni_vp); 194 keeporig: 195 /* Keep the original path; copy it back to the start of the buffer. */ 196 bcopy(ptr, buf, len); 197 return error; 198 } 199 200 void 201 linux_msg(const struct thread *td, const char *fmt, ...) 202 { 203 va_list ap; 204 struct proc *p; 205 206 p = td->td_proc; 207 printf("linux: pid %d (%s): ", (int)p->p_pid, p->p_comm); 208 va_start(ap, fmt); 209 vprintf(fmt, ap); 210 va_end(ap); 211 printf("\n"); 212 } 213